This invention relates to arthropodicidal solutions and more particularly to aqueous solutions effective in controlling phytophagous insects and arachnids characterized by enhanced arthropodicidal effectiveness and improved environmental compatability.
The use of insecticides has greatly enhanced agricultural productivity, but it has become apparent that there are limits to the amount of petrochemical based materials that safely can be absorbed into the environment. Catastrophic, unanticipated, relatively long term effects experienced with materials such as DDT have increased awareness of the potentially dangerous environmental impact of widespread use of synthetics, contributed to the creation of regulatory agencies charged with protecting the environment, and promoted the development of potent, but apparently less dangerous insecticidal materials made from petrochemicals. These new insecticides are nevertheless far from ideal from the point of view of environmental safety, and sometimes collect in food and fresh water resources.
Salts of fatty acids, primarily sodium or potassium fatty acid soaps, recently have been used as an insecticide. Compositions having excellent insecticidal properties which exploit these salts are available commercially under the trademark SAFER INSECTICIDAL SOAP. These fatty acid soaps are naturally occurring materials having no known long-term environmental effects. They are effective against mites and soft bodied insects such as aphids and whiteflies, but less effective against other types of arthropods.
While the mode of activity of monovalent metal salts of monocarboxylic fatty acids has not been elucidated, it is apparent that this type of active compound must be dissolved in water in order to exhibit its arthropodicidal activity. When concentrates of SAFER INSECTICIDAL SOAP are diluted with hard water, i.e., water containing significant quantities of calcium and/or magnesium ions, the monocarboxylic acid anions tend to precipitate leading to reduced arthropodicidal activity.
It is an object of this invention to provide an arthropodicidally active solution of monovalent metal salts of fatty acids which have potentiated arthropodicidal activity and which can be diluted with water from various sources, having various concentrations of hardness ions, without reducing the arthropodicidal activity of the solution per unit weight of active salt. Another object is to provide a method of protecting plants from phytophagous arthropods comprising applying to the plant a potentiated solution of monocarboxylic fatty acids or their monovalent metal salts.
These and other objects of the invention will be apparent from the following.